The present invention is directed to wheeled vehicles and, more particularly, to an apparatus for controlling the operation of a bicycle transmission.
Bicycles have transmissions that may be manually operated by the rider or automatically operated based on bicycle speed or some other parameter. Japanese Unexamined Patent Application (Kokai) 2001-10581 discloses an automatic transmission for a motorized bicycle wherein bicycle speed and pedal power are sensed. The transmission in that bicycle is housed within the rear wheel hub, and a controller selects the optimal transmission gear based on bicycle speed. The actual shifting of the transmission to the desired gear is timed to correspond to instances of decreased pedal power because smooth shifting cannot be accomplished when the transmission is subjected to large loads. Such timing is somewhat difficult in motor-assisted bicycles that tend to exert such large loads continuously. Furthermore, such systems require two-way communications between the controller and the motor and transmission, thus making for an extremely complicated control process. Such problems extend to both manual and automatic electronic transmissions.